So, I was messing around with double-extenders and testing the shortest delay I can have between powering pistons for both pistons to extend. Suddenly, I stumbled upon this design which, for no reason, not only extended both pistons, but retracted them simultaneously. I assumed this was a mechanic of the game, but when I attempted to replicate it for my other designs, due to it's simplicity, I found that this design can result in three different possibilities: (1) Both pistons extend and both retract back to their original positions, (2) both pistons will extend, but when both retract, the upper piston stays in place above the bottom piston instead of reverting back to the starting position, (3) or only the upper piston will extend and then retract. So, I wanted to test if this was based on chunk errors, x to y to z differences, etc. so I went into MCEdit and cloned up a total of 3,200 copies of identical designs in a mesh design. Now, I have only test about 460 of these, but as the pictures show, there is no apparent pattern. I am at a loss and I assume that most anyone else who witnesses this would be, as well. I browsed the issues and bugs open and resolved and found similar bugs, but nothing such as this. And this is not direction-based either, which is the reason I tested the last 60 before reporting. I assume this has to do with how each individual chunk updates, but it must be location-based as well for the reason that each individual contraption always has the same response. I color coated option (1) in green, option (2) in black, and option (3) in blue.